[Stoves] LPG comment

[Crispin Pemberton-Pigott]

Dear Friends

This is from an off-list discussion.  Paul Anderson felt it might be useful to others posted here, with a couple of corrections.

Regards
Crispin

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Subject: Re: Reuters Big Story: Smart gas cooking seeks to break African cities' dirty charcoal habit

LPG as an industry is highly regulated in terms of the safety of the equipment including the filling and storage facilities. I believe there are 29 different Standards for various elements of cooking stove system and fuel.

As to the fuel composition, however, it is still pretty wide open. The normal gas is not usually "pure propane" it is "liquid petroleum gas" in name only. Almost always, it is a blend of butane and propane with widely different proportions depending on the availability of gases. For example in South Africa it may be 20% butane and in India, 80%. There may be other hydrocarbons in the mix as small fractions. This is not such a pure chemical process as one might imagine it.

So as to the "quality" it doesn't really arise because these are so similar that the burner will deal with them well, if it is decent product. It is not gas quality that is tissue, but stove quality.

There is one proviso that has to-do with altitude. If you look at a natural gas (methane) stove it will have a rating for altitude. Above 7000 ft, for example, the burner should be replaced with a high altitude version in order to maintain burn quality. The same should apply to LPG however it more tolerant due to the fact it is a longer chain H-C.

In conclusion I can say that "gas" is always high quality with the only thing separating one from another being the energy content per kg (and it doesn't vary much - from 45 to 49 MJ/kg).

If anyone is interested I have a spreadsheet I can share created by James Robinson and me which calculates the energy content based on the gas composition ratio.

Regards
Crispin

From: cookswelljikos at gmail.com<mailto:cookswelljikos at gmail.com>
Subject: Re: Reuters Big Story: Smart gas cooking seeks to break African cities' dirty charcoal habit

Happy Eid all,

To follow up on this with a question,

This was in the news recently here -

''Mr Omtatah claimed that there are less restrictive means to achieve the purpose of reining in illegal and unsafe refilling of LPG cylinders besides abolishing the exchange pool.

"Ideally, the consumer should be at liberty to have his/her gas cylinder refilled by any qualified and licensed refiller irrespective of the brand. This is more so because the gas in the cylinders is not itself branded," he said.''

My question is how much does LPG gas quality vary for domestic cooking?

https://www.businessdailyafrica.com/economy/Omtatah-sues-energy-agency-/3946234-5228808-11nn8usz/index.html<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.businessdailyafrica.com%2Feconomy%2FOmtatah-sues-energy-agency-%2F3946234-5228808-11nn8usz%2Findex.html&data=02%7C01%7C%7C2199ac7ec5c348bc97d708d71f5f1254%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637012365497112949&sdata=FiXxYWcpVWQgKOc7huZ7K4keX2wBA1vkSWvRRYUkDDw%3D&reserved=0>

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